Fuel control device



Feb. 23, 1943. M. HANSEN FUEL CONTROL DEVICE Filed NOV. 22, 1940 .FUEL

' TANK AUXILIARY INVENTOR. MERLIN HANSEN MAIN FUEL ATTORNEYS.

Patented Feb. 23, 1943 FUEL CONTROL DEVICE Merlin Hansen, Waterloo, Iowa, assignor to John- Deere Tractor Company, Waterloo, Iowa, a corporation of Iowa Application November 22, 1940, Serial No. 366,559

4 Claims.

The present invention relates generally to fuel control devices and has for its principal object the provision of a control mechanism in a fuel burning apparatus, for automatically shifting the control of the fuel feed from one type of fuel to another, responsive to an operating condition in the fuel burning apparatus. One embodiment of my invention relates to internal combustion engines for service ,under conditions in which the engine operates a majority of the time under substantially full load, but is required to idle during extended periods which occur rather infrequently, such as, for example, engines for propelling tractors and other vehicles. In this type of service, it is conventional to use an aspiration type engine with spark ignition, operating on a comparatively low cost fuel oil. With'this type of engine it is customary to carry a supply of comparatively high grade, high cost fuel, such as gasoline, to

make it possible to start the engine readily and run it until it is warm enough to successfully burn the lower grade fuel. Although many different types of-engines can successfully burn fuel oil, when operating under a sustained substan-- tially normal load, very few engines can be successfully operated at idling speed and without load, for the reason that the engine cools down appreciably, making it difficult to carburet the fuel oil, with the result that it is dlmcult to keep the engine running during a long period of idling. Furthermore, after a period of idling operation, it is difllcult to load an /engine of this type without stalling.

It is a further object of my invention, therefore, to provid an internal combustion engine which normally burns low cost fuel under conditions of normal load, but which can be idled successfully, and after a period of idling can be made to readily carry its normal load without stalling.

In the accomplishment of these objects I have discovered that if the'fuel feed of the engine be switched from low grade to high grade fuel, as for example, the gasoline supply which is used for starting the engine, the engine will idle success-- fully for -long periods of time and then can be loaded successfully and switched back to the lower grade fuel without danger of stalling. A further object of my invention, therefore, has to do with the provision of a control device, which will automatically shift the fuel feed from low grade to high grade fuel as soon as the engine begins to idle, and to automatically shift backtolow grade fuel whenever the engine assumes its normal load once more. i

It is desirable to operate the engine on gasoline for a short time after it is loaded after a long period of idling to permit the temperature of the engine to rise to the point at which efficient carburetion of fuel oil is obtained. It is a further obiect of my invention to introduce an app ciahold of the engine.

ble delay between the change in load and a change in the type of fuel fed to the engine.

In the preferred embodiment of my invention I have provided a control device which is responsive to the pressure in the intake passage or man- When the engine is running at approximately full load, the throttle in the intake passage is nearly wide open and therefore the pressure in the passage is nearly equal to atmospheric pressure. When the engine is idling at no load, the throttle is nearly closed and the suction of the engine reduces the pressure in the intake passage or manifold to a partial vacuum, as is well-known to those skilled in the art. It is this change of pressur in the intake passage of the engine which is used in the preferred embodiment as a controlling factor for shifting the fuel feed from one fuel to the other. I

These and other objects and advantages of my invention will be apparent to those skilledzin the art after a consideration of the following description in which reference is had to the drawing appended hereto, in which Figure 1 is a longitudinal sectional elevation of a device embodying the principles of this invention: and

Figure '2 is a transverse sectional elevation taken along a line2.2 in Figure l.

Referringnow to the drawing, the internal combustion-engine is represented by a carburetor 5 of any suitabletype or construction, the details of which are-not concerned with, and an intake passage or manifold 6, rigidly connected to the carburetor 5 by suitable boltmeans I, through which the carbureted mixture flows from the carburetor to the engine cylinders. A damper or throttle valve 8 is disposed in the intakepassage between the jets of the carburetor (not shown) and the cylinders in order to control the rate of flow of the fuel mixture. The damper 8 is mounted on a vertical spindle 9 journaled in a boss 10 in the carburetor, and a control lever II is fixed to the upper end oi the spindle 9, for the purpose of rotating the damper valve 8 within the intake passage. Liquid fuel is fed to the carburetor 5 through a duct I2.

The low grade fuel is supplied to the engine from a main fuel tank l5 through a fuel feed conduit l6, and the high grade fuel is supplied from an auxiliary fuel tank l1 through a duct or conduit [8. The high grade fuel from the tank ill will be hereafter referred to as gasoline, since thatis the type of fuel which is preferred for this purpose.

The feeding of the fuel oil and gasoline to the carburetor is selectively controlled by means of a fuel feed control device, indicatedgenerally by reference numeral 28, comprising a housing 2|, in the opposite side walls of which are supported a pair of opposed fuel'valves 22, 23, respectively.

' receives therebetween the diaphragm 53.

in the side wall of the housing 2|, and the other end of which is internally threaded to receive a valve fitting 25 having a central duct 21 terminat ing in a valve port 23 at the inner end ofthe fitting 2 5. A valve pin 29 is slldable axially within the bushing 25 and has a tapered end 55 which is adapted to fit into the valve port 25 to interrupt the fiow of liquid fuel through the passage 27. Each of the fuel conduits I5, is is suitably coupled to the valve fittings 25, respectively, and a manually operated petcock 32 is connected in series with each of the supply ducts it, I 5.

The two valve pins 29 are disposed in alignment on opposite sides of the housing 2!! and are interconnected by a link 35 having downwardly turned ends 35 which are bifurcated to provide a slot 31 adapted to receive a stem 88 of reduced diameter rigidly fixed to the inner end of each of the valve pins 29. Each of the stems 38 is provided with a head 55 which fits between the downwardly turned end portion 35 and the body of the link 35. The link 55 is made of such a length that when either of the tapered ends 35 of the valve pins 29 is seated in its respective valve port 28, the other is nnseated to permit the flow of fuel through the valve. Each of the pins 29 is of a triangular cross section to maintain it centrally within the bushing but to provide passage for the liquid fuel through the bushing past the pin 29. Thus it is evident that by reciprocating the link horizontally along the axis of the bushings 25, the valve can be alternately opened and closed to permit the flow of one or the other of the fuels, selectively.-

Specifically, when the link is moved to the right, as viewed in Figure l, the right hand pin 29 is seated in the valve port 25, preventing the flow of gasoline through the duct it, while the left hand valve pin 29 is unseated from the valve port 28 and permitting the flow of fuel oil from the main tank l5 into the housing 2!.

The link 35 is reciprocated by means of an arm 40 pivotally mounted within the housing 2| on a pivot pin 6 I one end of which is journaled in a suitable bearing member 52 mounted in the back of the housing 2|, and the opposite end of the pivot pin 6| is journaled in a bearing member which is threaded into a suitable aperture in the cover plate 55 of the housing 2| and thus is adjustable along the axis of the pin 5| to adjust the amount of end play of the latter. The cover ll is rigidly attached to the housing 2| by suitable bolts 45. The upper end of the arm '55 is bifurcated to provide a pair of legs 55, which straddle the link 35, and each of the legs 55 is slotted at 4'! to receive a trunnion E8 rigidly mounted on the link 35. Thus, it is evident that by rocking the arm 40 about the supporting pivot pin 5|, the link 35 is reciprocated horizontally through the trunnion and slot connection with the arm 40.

The arm 40 is controlled by means of a rod 50, the end of which extends into a. slot 52 in the lower end of the arm} 40 and is pivotally ,connected to the latter by means of a pivot screw 5|. The rod is fixed to a diaphragm 53 by a rivet 54. v The diaphragm 53 is clamped between a pair of circular sheet metal cups 55. Each of the cupped members 55 is provided with a flange portion 56 which extends radially outwardly and One of the flanges 58 is then bent over the other to provide a secure support for the diaphragm 53 and which is sealed against passagecf gas or liquid from one side of the diaphragm to the other. The diaphragm case 55 is tightly secured by screws 57 against the plate 58 which is fixed to one side of the housing 2|, and the housing wall, the plate 58, and the case 55 are provided with aligned apertures 59 through which the connecting rod 58 extends between the diaphragm 53 and the arm 50.

The opposite side of the case 55 is provided with a tubular connecting portion 50, the end of which is threaded to receive a fitting 5| which connects the tubular portion 55 'to a duct 62. The duct establishes eommunication'between the intake passage or manifold 5 of the engine and the pressure chamber 53 between the diaphragm 53 and the case 55.

The diaphragm 53 is constructed of a thin fiexible material, preferably fibre or metal, and is adapted to move within the case 55 responsive to changes in pressure in the pressure chamber 53. A coil spring 54 is disposed within the tubular neck 60 and acts in compression between the duct fitting 5| and the diaphragm 55, tending to urge the latter toward the housing 2| and thus forcing the arm 50, through the rod 50, to swing in a clockwise direction about the pin 4|, thereby closing the gasoline valve 23 and opening the fuel oil valve 22, as illustrated in Figure 1. This is the normal position of the control device 20, so that for normal operation under substantially full load the engine operates on fuel oil fed from the main fuel tank l5, through the valve 22 into the housing 2| and through the discharge duct l2 connected into the lower portion of the housing 2| and conducting the fuel to the carburetor 5. Inasmuch as the throttle valve 8 is nearly wide open during full load operation, the pressure in the intake passage 5 is nearly atmospheric and-therefore there is not sumcient difierence in pressure between the atmosphere and the intake passage to overcome the pressure of the spring 54!, However, when the throttle valve 8 is closed, to idle the engine at no load, the suction of the engine creates an appreciable vacuum in the intake passage 5, thus reducing the pressure in the pressure chamber 63, whereby the fuel, which is under atmospheric pressure in the housing 2|, forces the diaphragm 53 toward the right, as viewed in Figure l, and thereby rocking the arm 40 about its pivot 4| to shift the link 35 toward the left. This closes the fuel oil valve 22 and opens the gasoline valve 23. The gasoline then mixes with the fuel oil in the housing 2|, and a gradual changeover to gasoline operation is effected, so that by the time the engine has cooled down the fuel oil has been consumed and the engine runs on straight gasoline, on which fuel it is able to successfully idle an indefinite period.

As soon as the throttle 8 is opened to load the engine, the vacuum in the intake passage 6 is relieved and thereby allows the spring 64 to return the diaphragm 53 to its normal position and thereby shifting from gasoline back'to fuel oil. By the time the fuel oil has replaced the gasoline in the housing 2| and duct i2, the engine is warm enough to operate successfully on fuel oil without danger of stalling.

In order to prevent the diaphragm 53 from fluttering back and forth due to momentary variations in pressure in the intak passage 6, the arm 40 is yieldingly held in either of the two positions by means of a toggle holding device including a short link l 0 having a ball portion 1|,

12 fixed at opposite ends thereof, respectively. The lower ball portion It is swingably seated in a bushing 13, which is screwed into an aperture 14 in the lower side of the housing 2|. The ball portion 12 at the upper end of the link l'is seated in a suitable recess 15 in the lower end of the arm 40 and is held firmly seated therein by means of a coil spring 16 disposed in a recess I1 under the ball portion II. The action of the spring I6 tends to hold the arm 40 in either of its extreme positions and insures that the link 35 is not balanced for any appreciable length of time in an intermediate position in which both 1. In an internal combustion engine of the aspiratlon type adapted to operate on either of two fuels and having conduits for supplying each of said fuels and an intake passage, a device for selectively controlling the feeding of one or the other of said fuels, said device comprising a housing having. a mixing chamber, a pair of fuel valves supported by said housing and connected with said conduits, respectively, to control the flow of each fuel into said chamber, a discharge duct connected with said chamber for conducting fuel to said engine, a reciprocable member engaging said valves to open one of the Valves and close the other when said member is reciprocated in one direction and vice versa, link means connected to said member for reciprocating the latter, a pressure responsive member connected to said link means, a compartment in which said pressure responsive member is reciprocably disposed, said compartment being disposed in communication with said intake passage whereby a drop in pressure in the latter causes said pressure responsive member to move in one direction to operate said valves and thereby changing from operation on one of said fuels to the other, and means for returning said pressure responsive member toward its normal position when the pressure in said intake passage rises beyond a certain value. I

2. In an internal combustion engine of the aspiration type adapted to operate on either of two fuels and having conduits for supplyi each of said fuels and an intake passage, a device for selectively controlling the feeding of one or the other of said fuels. said device comprising a housing, a pair of fuel valves supported thereby and connected with said conduits, respectively, to control the flow of each fuel into said housing, there being a mixing chamber in said housing for receiving fuel from said valves and a discharge duct for conducting fuel from said chamber to the engine, said valves being disposed on opposite sides of said housing and having opposed aligned stems movable longitudinally to open and close the valves, a reciprocable link within said housing interconnecting said stems and adapted to close one valve and open the other when said link is moved in one direction, and vice versa, an arm pivotally mounted in said housing and'connected with said link to reciprocate the latter, a pressure responsive member connected with said arm,

a compartment in which aid pressure responsive member is reciprocally disposed fixed to said housing in communication therewith, and duct means connecting said compartment with a part of the engine for controlling said pressure responsive member.

3. In an internal combustion engine of the aspiration type adapted to operate on either of two fuels and having conduits for supplying each of said fuels and an intake passage, a device for selectively controlling the feeding of One or the other of said fuels, said device comprising a housing having a mixing chamber, a pair of fuel valves supported by said housing and connected with said conduits, respectively, to control the flow of each fuel into said chamber, a discharge duct for conducting the fuel to said engine, said valves being disposed on opposite'sides of the housing and having opposed aligned stems movable longitudinally to open and close the valves, a valve actuating member disposed between said stems and reciprocable to open and close said valves alternately to control the feeding'of said fuels, selectively, an arm pivotally supported in said housing and connected with said valve actuating member to reciprocate the latter, a pressure responsive member connected with said arm,

a compartment in which said pressure responsive member is reciprocally disposed, duct means connecting said compartment with the intake passage of the engine, whereby a drop in pressure in the latter causes said pressure responsive member to move in one direction to operate said valves and thereby changing from operation on one of said fuels to the other, and means for returning said pressure responsive member toward its normal position when the pressure in said intake passage rises beyond a certain value.

4. In an internal combustion engine of the aspiration type adapted to operate on either of twofuels and having conduits for supplying each of said fuels and an intake passage, a device for selectively controlling the feeding of one or the other of said fuels, said device comprising a housing having a mixing chamber, a pair of fuel valves supported by said housing and connected with said conduits, respectively, to control the flow of each fuel into said chamber, a discharge duct for conducting the fuel to said engine, said valves having opposed, aligned stems on opposite sides of the mixing chamber, a valve actuating member disposed in said chamber between said stems and reciprocable to open and close said valves alternately to control the feeding of said fuels, selectively, an arm pivotally supported in said mixing chamber and connected with said valve actuating member to reciprocate the latter, a compartment disposed in communication with said chamber, a pressure responsive member reciprocally disposed in said compartment and dividing the latter, means coupling one side of said pressure responsive member with said arm to actuate the latter, duct means connecting said compartment on the opposite side of said pressure responsive member with the intake passage of the engine, whereby a drop in pressure in the latter causes said pressure responsive member to move in one direction to operate said valves and thereby changing from operation on one of said fuels to the other, and means for returning said pressure responsive member toward its normal position when the pressure in said intake passage rises beyond a certain value.

MERLIN HANSEN. 

